In general, in the finishing system art there are known means for connecting insulated panel members in an end-to-end relationship, such as shown in U.S. Pat. No. 3,376,678. The main objective in manufacturing insulated panels is to provide a panel which is easily assembled at a job site, and that can minimize the heat loss from the inside of the oven to the outside of the oven once the panels are joined together. In addition, the seal between abutting panel members must be able to expand and contract during the heating and cooling cycle of the oven. Most of the prior art insulated panels are connected by clips which have a tendency to loosen and back out due to the stresses caused by expansion and contraction. This further reduces the sealing capabilities of the prior art panels. Some prior art panels have the locking clips welded in place, making field replacement difficult and the welds can create hot spots as well as being subject to cracking. Although the prior art discloses panels which are joined in an interlocking relationship, there remains the problem of excessive heat loss through the seal and the inability of panels and seals to expand and contract during the heating and cooling cycles.